package 深度优先_广度优先;

public class LeetCode572_另一棵树的子树 {
      private class TreeNode {
      int val;
      TreeNode left;
      TreeNode right;
      TreeNode() {}
      TreeNode(int val) { this.val = val; }
      TreeNode(int val, TreeNode left, TreeNode right) {
          this.val = val;
          this.left = left;
          this.right = right;
      }
  }
    public boolean isSubtree(TreeNode root, TreeNode subRoot) {
        if(root == null && subRoot == null){
            return true;
        }
        if(root == null){
            return false;
        }
        if(subRoot == null){
            return true;
        }
        if(isSameTree(root,subRoot)){
            return true;
        }
        return isSubtree(root.left,subRoot) || isSubtree(root.right,subRoot);
    }

    public boolean isSameTree(TreeNode p,TreeNode q){
        if(p == null && q == null){
            return true;
        }
        if(p == null || q == null){
            return false;
        }
        if(p.val != q.val){
            return false;
        }
        return isSameTree(p.left,q.left) && isSameTree(p.right,q.right);
    }
}
